The present invention relates to a multiplex broadcast receiver having a sound multiplex demodulator circuit, and in particular, to a sound multiplex broadcast receiver and a method of controlling display thereof in which modes of sound output signals from the receiver can be displayed.
In a sound multiplex broadcast receiver (for example, a television receiver) for use in a sound multiplex broadcast system of the United States of America (U.S.) and/or Japan, display of a sound multiplex receiving mode according to detection of presence or absence of a broadcast sound multiple signal and display of a sound multiplex setting mode established by the user are controlled in general by a light-emitting diode or a switching device as described, for example, in page 34 of the "Television Technology", Nov. 1978. However, recently, thanks to adoption of a cathode-ray tube (CRT) screen for the display operations, the receiving and setting modes above are displayed on the CRT display for the control operations thereof.
Moreover, in the receiver of this kind, the state of mode is not displayed for the sound output signal from the receiver. Consequently, to discriminate the mode of the output signal, the user has been required to check presence or absence of the display of the sound multiplex reception mode and the display of the mode established by the user.